Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: PmbPhy on 09/09/2015 18:35:17

Title: Where do definitions come from?
Post by: PmbPhy on 09/09/2015 18:35:17
I've always considered textbooks to be the source of definitions when it comes to terminology. I was wondering who else thinks this way?
Title: Re: Where do definitions come from?
Post by: timey on 09/09/2015 18:42:52
Well this Pete, IMHO, this is dependent on the textbook itself.  It also depends on wether the matter that one try's to define has 'already' been defined.  When trying to define a matter that is yet to be defined, 'any' textbook is rendered useless. Edit: This being based on the fact that terminology is subject to context when in use.
Title: Re: Where do definitions come from?
Post by: PmbPhy on 09/09/2015 18:53:47
Well this Pete, IMHO, this is dependent on the textbook itself.  It also depends on wether the matter that one try's to define has 'already' been defined.  When trying to define a matter that is yet to be defined, 'any' textbook is rendered useless. Edit: This being based on the fact that terminology is subject to context when in use.
I'm referring to terms that are already defined.

Why do you say that its dependent on the textbook?
Title: Re: Where do definitions come from?
Post by: timey on 09/09/2015 19:15:00
I'm referring to terms that are already defined.

:) Ok fair enough, and I shall concede to your point, my point only arising from something I am considering elsewhere.  Nothing is already defined, but in the context of what came before the moment of creation, nothing may not be defined and a definition in this context is not actually available.

Why do you say that its dependent on the textbook?

Perhaps we come to the point where you may have to define the terminology 'textbook' to me.  Perhaps this is 'school' oriented.  I have read a lot of books.  If I want a word defined I refer to the net.
Text book dependent?  I have read many books that define general relativity, some are much better at it than others.  This is what I mean.
Title: Re: Where do definitions come from?
Post by: chiralSPO on 09/09/2015 19:26:26
I guess it depends on what you're trying to find definitions of. IUPAC has a pretty good collection of well-defined constants, and their precise "accepted" (defined) values. They also define units and quantities.

http://goldbook.iupac.org/list_math.html
Title: Re: Where do definitions come from?
Post by: timey on 09/09/2015 20:09:39
That's a useful link!  Armed with this, Pete's cosmology text book, inclusive of a list of cosmological terms in relation to mathematical symbols, and Alan's link on dimensional analysis... all I need is a concise depiction of the rules of algebra - and I can start teaching myself how to do the math. :)
Title: Re: Where do definitions come from?
Post by: alancalverd on 10/09/2015 00:00:15
Quote
The definitions of the terms "quantity", "unit", "dimension" etc. that are used in the SI Brochure are those given in the International vocabulary of metrology, a publication produced by the Joint Committee for Guides in Metrology (JCGM), a working group consisting of eight international standards organisations under the chairmanship of the director of the BIPM.[36] The quantities and equations that define the SI units are now referred to as the International System of Quantities (ISQ), and are set out in the International Standard ISO/IEC 80000 Quantities and Units.

There are umpteen internationally recognised derived quantities and units that cover pretty much every need in science. If you need to invent a new quantity, or if you discover a new phenomenon, the name and definition rest with the inventor/discoverer, but as with everyday language, names and definitions tend to evolve: I doubt whether many people nowadays would seek a skiagram or a zeugmatogram when x-rays and MRI scans are available.

There are also international committees for the naming of species, minerals and cosmic objects.
Title: Re: Where do definitions come from?
Post by: mathew_orman on 10/09/2015 08:42:52
They come from knowledge of logic...
If you declare an atom then you must define it meaning declare its structure and properties...
In physics usually you would first discover an entity of matter and then, based on experimental result declare its structure and properties...
Title: Re: Where do definitions come from?
Post by: lightarrow on 10/09/2015 12:30:41
I've always considered textbooks to be the source of definitions when it comes to terminology. I was wondering who else thinks this way?
An example of the sort of definition you have in mind?

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lightarrow
Title: Re: Where do definitions come from?
Post by: PmbPhy on 10/09/2015 13:58:37
Quote from: chiralSPO
I guess it depends on what you're trying to find definitions of.
As I said in my opening point, I'm asking about definitions on terminology. Constants don't fall into that class.
Title: Re: Where do definitions come from?
Post by: PmbPhy on 10/09/2015 14:00:03
I've always considered textbooks to be the source of definitions when it comes to terminology. I was wondering who else thinks this way?
An example of the sort of definition you have in mind?

-
lightarrow
E.g. the terms scalar and 4-vector.
Title: Re: Where do definitions come from?
Post by: alancalverd on 11/09/2015 18:41:26
They come from knowledge of logic...
If you declare an atom then you must define it meaning declare its structure and properties...
In physics usually you would first discover an entity of matter and then, based on experimental result declare its structure and properties...

We name things when we require a cause. Thus atoms were named as such about 2000 years before anyone even thought they had a structure.